Centrifugal casting machine



July 3, 1956 A. BOSNA 2,752,553

CENTRIFUGAL CASTING MACHINE Filed May 11, 1954 M INEN w! Afizzanar 14. 50.5fm

BY 5% M 1 ATTORNEYS 2 Claims. (Cl. 2265.1)

This invention relates generally to improvements in casting apparatus and, more particularly,

is tne provision,

cision castings.

The above and other objects, features and advantages of the present invention will be more fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawing which illustrates the best mode now contemplated by me for carrying out my invention:

Fig. l is a perspective view of centrifugal casting apparatus formed according to the present invention;

Fig. 2 is a top view thereof;

Fig. 3 is a sectional view, on an enlarged scale, taken on the line 33 of Fig. 1;

Fig. 4 is a sectional view, on an enlarged scale, taken on the line 44 of Fig. 1;

Fig. 5 is a bottom view of the apparatus with the base shown removed;

Fig. 6 is a sectional view Fig. 2; and

Fig. 7 is a perspective view of the mold or flask.

Referring to the drawing in detail, the centrifugal casting apparatus 19 is of the type generally shown and described in the patent to Herbert R. Berger No. 2,245,065, dated June 10, 1941, for Dental Casting Machine, and assigned to the of power which is adapted to rotate the shaft 14 at high speed, said shaft having a horizontally disposed longitudinally extending bar or member 16 detachably secured thereto, as best shown in Fig. 4. The bar or member 16 is provided with a centrally disposed aperture 13 which is adapted for the reception of the threaded end portion 20 of the upwardly projecting shaft 14, said threaded end portion being adapted for the reception of the nut 22 for firmly clamping the bar 16 into operative association with the taken. on the line 66 of 2,752,650 Patented July 3, 1956 ice or melting furnace 28 is rigidly secured to the bar 16 by means of the removably secured to the outer casing of the heating chamber 28 by means of the bolts 34. The heating chamber 28 is generally of the type shown and described in the above referred to patent and is assembled to the bar 16 in the manner shown and described in said patent. A contact block 36 is ports the flask 44 in a disposition in Which said flask is slotted as indicated at 54 for the reception of the bar 16, it being apparent that said holder is slidably movable along said bar toward and away from the axis of rotation of the bar.

The heating chamber 28, the flask 44, and the holder 46 are mounted on the bar 16 on one side of the axis of rotation thereof and to counterbalance said bar, there is provided a cylindrical counterweight 56 which is slidably mounted on said bar on the opposite side of the axis of rotation thereof. The counterweight 56 is slotted as indicated at 58 for the reception of associated portions of the bar 16 and said counterweight is mounted in fixed relation with the holder 46 by means of the pair of longitudinally extending coupling members 60. The ends 62 of the members 60 are threaded as shown in Fig. 5 and are threadedly receivable in the tapped apertures 64 provided in the counterweight 56. The opposite ends 66 of the members 60 are adapted to extend through apertures 68 of the holder 46 nuts. Thus, the holder 46 and counterweight 56 are the bar 16 and on the rotation of said bar the counterweight 56 will be effective'to centrifugally urge the holder 4.6 towards the heating chamber 28 for clamping the flask 44 against said chamber in operative association therewith. The counterweight 56 is restrained from disengagement with the bar 16 and for sliding movement therealong by means of the U-shaped part 72 which is secured to said counterweight, there being provided a tension spring 74 having one end 76 secured to said part with the opposite end 78 thereof being fixed to the part 80 carried by said bar, said spring being effective to resiliently urge the counterweight 56 away from the axis of rotation of the bar 16 so as to resiliently urge the holder 46 into clamping engagement with the flask 44. Accordingly, when the bar 16 is stationary the holder 46 will resiliently urge the flask 44 into operative association with the heating chamber 28, it being understood that the spring 74 is a relatively weak spring and while said spring is sufficient to effect the initial clamping engagement between the flask 44 and the chamber 28, the holder 46 may be readily retracted from the flask 44 for removing the latter from the apparatus. Once the bar 16 is released for rotation the centrifugal force of the counterbalancing masswill urge the heating chamber 28 and flask 44 into clamped operative engagement, it being understood that the counterweight 56 and holder 46 are mounted in unitary relation for sliding movement along the bar 16. Accordingly, the greater the centrifugal force created by the rotation of the counterweight 56 the greater will be the clamping effect of the holder 46.

in order to limit the movement of the counterweight 56 towards the axis of rotation of the bar 16, there is provided a stop device 82 which is fixed to the bar and which is adapted to coact with a peripheral portion of the counterweight to limit the movement thereof towards said axis. The counterweight 56 is provided with a centrally disposed upstanding shaft 84 which is adapted for the reception of one or more additional counterweights 86, said shaft also facilitating the winding up of the spring type motor in the base 12. Thus sufficient counterweights 86 may be removably stacked on the counterweight 56 to balance the mass on the opposite side of the axis of rotation of the bar 16.

In practice as described in the aforereferred to patent, the shaft or handle 84 is rotated to wind up the spring motor in the base 12 and the slidable contact plate 40 is then moved out into the path of the contact block 36 against the tension of the contact plate spring. The pressure of the spring motor forces the contact block firmly against the slidable contact plate and retains it in the extended or projected position. The circuits to the heating element and thermocouple of the heating chamber 28 are now closed and the mold or flask 44 is positioned in the cradle 42 and is clamped into operative engagement with the heating chamber 28, it being understood that the initial clarnping force for the holder 46 is obtained by means of the spring 74. When the desired operating conditions are obtained, the bar 16 is released for rotation and on the rotation of such bar the counterweight 56, which is in fixed relation with the holder 46, will be effective to centrifugally urge the portion 48 of holder 46 against the flask to thereby clamp the latter against the heating chamber 28, the greater the centrifugal force created by the counterweight 56 the greater will be the clamping force of the holder 46.

From the above it will be apparent that the counterweight 56 is operatively connected to the flask holder 46 whereby the latter is adapted to clamp the flask or mold 44 against the discharge end of the heating chamber 28 on the rotation of the bar 16. Thus apparatus has incorporated therein an improved arrangement for counterbalancing the centrifugal force created by the heating chamber and flask during their rotation in which the centrifugal-force of the counterbalance 56 or counterbalancing mass is utilized to urge the heating chamber and flask into clamped operative engagement.

The members 60 constitute means for coupling counterweight 56 and the holder '46for"movement in unison along the bar 16, and while a specific coupling arrangement has been illustrated and described it will be understood that any suitable arrangement may be provided for effecting the coupling between said counterweight and holder. The flask holder 46 may be adjusted to clamp molds of various sizes while the counterweights may be adjusted in the aforedescribed manner to properly balance the bar 16.

While I have shown and described the preferred embodiment of my invention, it will be understood that various changes may be made in the present invention without departing from the underlying idea or principles of the invention within the scope of the appended claims.

aving thus described my invention, what I claim and desire to secure by Letters Patent, is:

l. in centrifugal casting apparatus having a member mounted for rotation about an axis, a heating chamber carried by said member, a flask holder mounted for movement on said member towards one end of said heating chamber on the rotation of said member and being adapted to clamp a flask against said end of the heating chamher, the latter and said flask holder being disposed on one side of said axis, and counterweight means mounted for movement on said member towards and away from said axis on the opposite side thereof, said counterweight means being operatively connected to said holder whereby the latter is adapted to clamp 21 flask against said end of the heating chamber on the rotation of said member, said member comprising a longitudinally extending bar and said holder and counterweight means being slotted to slidably receive said bar, said counterweight means comprising a member of cylindrical formation having a provision for removably receiving additional counterweight members in superposed relation to said cylindrical member.

2. Centrifugal casting apparatus comprising a base, a longitudinally extending bar rotatably carried by said base, a heating chamber carried by said bar in fixed relation therewith, means mounted on said bar for supporting a flash in position for receiving a charge from said heating chamber when said bar is rotated, means for clamping the receiving end of said flask against the discharge end of said chamber, counterweight means mounted in fixed relation with said clamping means, said counterweight means and said clamping means being slotted to slidably receive said bar for movement therealong relative to said heating chamber, said heating chamber, said flask supporting means, and said clamping means being mounted on one side of the axis of rotation of said bar and sa d counterweight means being mounted on the opposite side thereof whereby the rotation of said bar is effective to centrifugally urge said clamping means towards said chamber for clamping said flask against said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,142,840 Pankratz June 15, 1915 1,304,118 Stokes May 20, 1919 1,498,562 Maupin June 24, 1924 1,915,887 Hinricks June 27, 1933 1,944,163 Bellows Jan. 23, 1934 1,949,021 Leuser Feb. 27, 1934 2,024,615 Touceda Dec. 17, 1935 2,245,065 Berger June 10, 1941 2,385,631 Leviuson Sept. 25, 1945 2,451,103 Loew Oct. 12, 1948 2,515,216 Guelph July 18, 1950 2,612,443 Goetzel et a1. Sept. 30, 1952 FOREIGN PATENTS 361,322 Great Britain Nov. 16, 1931 703,828 Great Britain Feb. 10, 1954 

1. IN CENTRIFUGAL CASTING APPARATUS HAVING A MEMBER MOUNTED FOR ROTATION ABOUT AN AXIS, A HEATING CHAMBER CARRIED BY SAID MEMBER, A FLASK HOLDER MOUNTED FOR MOVEMENT ON SAID MEMBER TOWARDS ONE END OF SAID HEATING CHAMBER ON THE ROTATION OF SAID MEMBER AND BEING ADAPTED TO CLAMP A FLASK AGAINST SAID END OF THE HEATING CHAMBER, THE LATTER AND SAID FLASK HOLDER BEING DISPOSED ONE SIDE OF SAID AXIS, AND COUNTERWEIGHT MEANS MOUNTED FOR MOVEMENT ON SAID MEMBER TOWARDS AND AWAY FROM SAID AXIS ON THE OPPOSITE SIDE THEREOF, SAID COUNTERWEIGHT MEANS BEING OPERATIVELY CONNECTED TO SAID HOLDER WHEREBY THE LATTER IS ADAPTED TO CLAMP A FLASK AGAINST SAID END OF THE HEATING CHAMBER ON THE ROTATION OF SAID MEMBER, SAID MEMBER COMPRISING A LONGITUDINALLY EXTENDING BAR AND SAID HOLDER AND COUNTERWEIGHT MEANS BEING SLOTTED TO SLIDABLY RECEIVE SAID BAR, SAID COUNTERWEIGHT MEANS COMPRISING A MEMBER OF CYLINDRICAL FORMATION HAVING A PROVISION FOR REMOVABLY RECEIVING ADDITIONAL COUNTERWEIGHT MEMBERS IN SUPERPOSED RELATION TO SAID CYLINDRICAL MEMBER. 